Fluid injection device

ABSTRACT

A fluid injection device includes: a pulse generator which converts fluid into pulse flow; a suction pipe projecting from the pulse generator; an injection pipe which is eccentrically inserted into the suction pipe such that the outer circumferential surface of the injection pipe contacts the inner circumferential surface of the suction pipe, and has an injection opening communicating with the pulse generator; and a suction channel and a suction opening formed between the inner circumferential surface of the suction pipe and the outer circumferential surface of the injection pipe, wherein the injection pipe is fixed to the inner circumferential surface of the suction pipe in the vicinity of the injection opening.

This application claims priority to Japanese Patent Application No.2010-046299, filed on Mar. 3, 2010, the entirety of which is herebyincorporated by reference.

BACKGROUND

1. Technical Field

The present invention relates to a fluid injection device including aninjection pipe and a suction pipe.

2. Related Art

A method for excising, incising, and crushing a living tissue by using afluid injection device has preferable characteristics as a surgicalinstrument such as capabilities of preventing heat damage and preservingblood vessels and other capillary tissues. When an operation isperformed using the fluid injection device, injected liquid, excisedtissues or the like which remains on the portion of surgery becomes anobstacle for securing vision in some cases. As a technology forovercoming this problem, such a fluid injection device further includinga suction pipe capable of removing liquid or excised tissues by suctionis known.

As an example of this type of fluid injection device, a device which hasan injection pipe for injecting high-pressure fluid as a pipe disposedwithin a suction channel of a suction pipe in such a position as to beconcentric with the suction channel has been proposed (seeJP-A-1-313047).

Another example of the fluid injection device currently proposedincludes an injection pipe for injecting high-pressure fluid as a pipeinserted eccentrically with respect to the inner circumferential surfaceof a suction pipe (see JP-A-6-90957).

A further example of the fluid injection device sharply changes thevolume of a fluid chamber by using a volume varying unit to convertfluid into pulse flow and inject the pulse flow through an injectionopening as pulses at high speed (see JP-A-2008-82202).

According to the technology disclosed in JP-A-1-313047, the innercircumferential surface of the suction pipe and the outercircumferential surface of the injection pipe are concentricallydisposed. Thus, the size of the suction channel at a suction opening(the length of the clearance between the inner circumferential surfaceof the suction pipe and the outer circumferential surface of theinjection pipe) becomes half of the difference between the insidediameter of the suction pipe and the outside diameter of the injectionpipe. In this case, it is difficult to remote excised tissues largerthan the size of the suction channel at the suction opening by suction.When the diameter of the suction pipe is increased to secure thesufficient size of the suction channel, the vision for surgery isnarrowed.

According to the technology disclosed in JP-A-6-90957, the injectionpipe is inserted eccentrically to the inner circumferential surface ofthe suction pipe. In this case, the size of the suction channelcorresponds to the difference between the inside diameter of the suctionpipe and the outside diameter of the injection pipe, and thus becomeslarger than the size of the suction channel in the concentric structureshown in JP-A-1-313047 when the suction pipe and the injection pipe havethe same diameters as those in the concentric structure. However, thereis a possibility that vibration is generated at the top end of theinjection pipe, that is, in the vicinity of the injection opening at thetime of injection of high-pressure fluid. In this case, injection offluid toward the target surgery portion becomes difficult.

Moreover, according to the structure which inserts the injection pipeeccentrically to the suction pipe as the structure shown inJP-A-6-90957, the position of the injection opening cannot be directlyrecognized by visual check. Thus, injection of fluid to the accurateposition of the target surgery portion is difficult.

According to the fluid injection device disclosed in JP-A-2008-82202,excision can be achieved by using a smaller amount of fluid than theamount of high-pressure fluid injected as continuous streams used by themethods shown in JP-A-1-313047 and in JP-A-6-90957. In case of thestructure disclosed in JP-A-2008-82202, however, there is a case inwhich a suction pipe is required for improvement of visualrecognizability of the surgery portion or for removal of excised tissuesby suction. In this case, the injection pipe can be insertedeccentrically to the inner circumferential surface of the suction pipefor increasing the size of the suction channel as in the structure shownin JP-A-6-90957. However, when fluid is injected as pulses in thisstructure, it is expected that vibration of the injection pipe becomeslarger than vibration generated by continuous flow injection.

When vibration is generated on the injection pipe, abnormal noise isproduced by contact between the injection pipe and the suction pipe.Moreover, when the suction pipe is resonated by vibration generated atthe top end of the injection pipe (injection opening), injection offluid toward the surgery portion becomes difficult.

SUMMARY

An advantage of some aspects of the invention is to provide a technologycapable of solving at least a part of the problems described above andthe invention can be implemented as the following forms or applicationexamples.

Application Example 1

This application example of the invention is directed to a fluidinjection device which includes: a pulse generator which converts fluidinto pulse flow; a suction pipe projecting from the pulse generator; aninjection pipe which is eccentrically inserted into the suction pipesuch that the outer circumferential surface of the injection pipecontacts the inner circumferential surface of the suction pipe, and hasan injection opening communicating with the pulse generator; and asuction channel and a suction opening formed between the innercircumferential surface of the suction pipe and the outercircumferential surface of the injection pipe. In this case, theinjection pipe is fixed to the inner circumferential surface of thesuction pipe in the vicinity of the injection opening.

According to this application example, the injection pipe iseccentrically inserted into the suction pipe. In this case, the size ofthe suction channel corresponds to the difference between the insidediameter of the suction pipe and the outside diameter of the injectionpipe. When the inside diameter of the suction pipe and the outsidediameter of the injection pipe are d1 and d2, respectively, the size ofthe suction channel (length of clearance) is expressed as d1−d2. On theother hand, according to a structure which concentrically disposes thesuction pipe and the injection pipe, the size of the suction channelcorresponds to (d1−d2)/2. In this case, the size of the suction channelin the eccentric structure becomes larger than the size of the suctionchannel in the concentric structure. Thus, larger excised tissues can besucked in the structure in which the injection pipe and the suction pipeare eccentrically disposed than in the structure in which the injectionpipe and the suction pipe are concentrically disposed. In addition, theremoval amount of injected drainage increases, providing preferablevision for surgery.

According to this structure, the injection pipe is fixed to the innercircumferential surface of the suction pipe in the vicinity of theinjection opening. Thus, abnormal noise produced by contact between theinjection pipe and the suction pipe caused by vibration at the top endof the injection pipe is prevented by reduction of the vibrationthereat. Moreover, movement of the top end of the injection pipe(injection opening) caused by the vibration thereat and resonance of thesuction pipe generated by the vibration can be both prevented. Thus,fluid can be accurately injected toward the surgery portion.

Application Example 2

This application example of the invention is directed to the fluidinjection device of the above application example, wherein a markindicating the position of the injection opening is provided on thesuction pipe in the vicinity of the suction opening.

According to the structure which eccentrically inserts the injectionpipe into the suction pipe, an operator can recognize the position ofthe injection opening based on the mark indicating the position of theinjection opening. Thus, fluid can be accurately injected toward thesurgery portion.

Application Example 3

This application example of the invention is directed to the fluidinjection device of the above application example, wherein the mark is anotch formed in such a position as to overlap with the periphery of thesuction opening, or a through hole opened in the vicinity of the suctionopening.

The mark may be a seal or the like which indicates the position of theinjection opening provided in the vicinity of the suction opening. Whena notch as the mark is formed in such a position as to overlap with theperiphery of the suction opening, the notch not only allows recognitionof the position of the injection opening but also increases the size ofthe suction opening by the amount corresponding to the notch.

When the mark is constituted by a through hole, excised tissues on theside surface as well as excised tissues at the top end can be removed bysuction.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 illustrates the structure of a fluid injection device as asurgical instrument according to a first embodiment.

FIG. 2 is a cross-sectional view illustrating cross sections of a pulsegenerator, an injection pipe, and a suction pipe cut in the injectiondirection of fluid according to a first example.

FIGS. 3A and 3B are cross-sectional views showing cross sections takenalong a line A-A in FIG. 2, wherein: FIG. 3A illustrates the firstexample; and FIG. 3B illustrates a related art.

FIG. 4 is a partial cross-sectional view illustrating the structure ofan injection pipe and a suction pipe according to a second example.

FIG. 5 is a partial cross-sectional view illustrating the structure ofan injection pipe and a suction pipe according to a third example.

FIG. 6 is a partial cross-sectional view illustrating the structure ofan injection pipe and a suction pipe according to a fourth example.

FIG. 7 is a partial cross-sectional view illustrating the structure ofan injection pipe and a suction pipe according to a fifth example.

FIG. 8 is a partial cross-sectional view illustrating the structure ofan injection pipe and a suction pipe according to a sixth example.

FIGS. 9A and 9B show top ends of an injection pipe and a suction pipeaccording to a seventh example, wherein: FIG. 9A is a cross-sectionalview; and FIG. 9B is a front view as viewed from the top ends (in thedirection indicated by an arrow E).

FIG. 10 is a front view illustrating a top end of a suction pipeaccording to an eighth example.

DESCRIPTION OF EXEMPLARY EMBODIMENT

An exemplary embodiment according to the invention is hereinafterdescribed with reference to the drawings.

The figures referred to in this embodiment are shown only as schematicsthe reduction scales of which for components and parts in the verticaland horizontal directions are different from the actual scales forconvenience of easy understanding of the figures.

First Embodiment

FIG. 1 illustrates the structure of a fluid injection device as asurgical instrument according to a first embodiment. Thus, fluid used inthis embodiment described herein is constituted by physiological saltwater. As illustrated in FIG. 1, a fluid injection device 1 includes afluid supply container 2 for containing fluid, a supply pump 10 as afluid supply unit, a pulse generator 20 for converting fluid suppliedfrom the supply pump 10 into pulse flow (hereinafter referred to aspulse flow as well), an injection pipe 70 communicating with the pulsegenerator 20, a suction pipe 80 projecting from the pulse generator 20,a suction pump 11 as a suction unit, and a drainage container 3 forcontaining sucked drainage and excised tissues. The pulse generator 20,the supply pump 10, and the fluid supply container 2 are connected by afluid supply tube 4. The suction pipe 80, the suction pump 11, and thedrainage container 3 are connected by a suction tube 5.

The pulse generator for generating pulse flow may be operated by varioussystems such as a piezoelectric system including a piezoelectricelement, and a bubble jet (trademark) system as long as the systems canconvert fluid into pulse flow and inject the pulse flow as pulses. Inthe following explanation, a pulse generator operated by thepiezoelectric system is discussed as an example.

The injection pipe 70 has an injection channel 71 communicating with afluid chamber 60 formed within the pulse generator 20. An injectionopening 72 having a narrowed flow channel is opened at the top end ofthe injection pipe 70.

The injection pipe 70 is eccentrically inserted into the suction pipe 80such that the outer circumferential surface of the injection pipe 70contacts the inner circumferential surface of the suction pipe 80. Theinjection pipe 70 is fixed to the inner circumferential surface of thesuction pipe 80 in the vicinity of the injection opening 72 by bondingor other fixing methods. The clearance formed between the innercircumferential surface of the suction pipe 80 and the outercircumferential surface of the injection pipe 70 corresponds to asuction channel 81 and a suction opening 82. The injection pipe 70 isrigid enough to avoid deformation during injection of fluid. It ispreferable that the suction pipe 80 is more rigid than the injectionpipe 70.

The flow of fluid within the fluid injection device 1 constructed asabove is now briefly explained. Fluid contained in the fluid supplycontainer 2 is sucked by the supply pump 10, and supplied through thefluid supply tube 4 toward the pulse generator 20 at a constantpressure. The pulse generator 20 has the fluid chamber 60, apiezoelectric element 30 as a volume varying unit for varying the volumeof the fluid chamber 60, and a diaphragm 40. The pulse generator 20generates pulse flow within the fluid chamber 60 by driving thepiezoelectric element 30, and injects the fluid having passed throughthe injection channel 71 as pulses from the injection opening 72 at highspeed.

While the operation of the pulse generator 20 is stopping, that is,while the volume of the fluid chamber 60 is not being changed, the fluidsupplied from the supply pump 10 at the constant pressure passes throughthe fluid chamber 60 and goes out of the injection opening 72 ascontinuous streams for injection.

The pulse flow herein refers to flow of fluid which has a constant flowdirection but has a flow amount or a flow speed varying periodically orirregularly. The pulse flow includes intermittent flow where fluidrepeats a cycle of flow and stop. However, the pulse flow may be flowother than the intermittent flow as long as the flow amount or the flowspeed of fluid changes periodically or irregularly.

Similarly, injection of fluid as pulses refers to injection of fluidwhose flow amount or moving speed varies periodically or irregularly.The injection as pulses includes intermittent injection which repeats acycle of injection and non-injection of fluid, for example. However, theinjection as pulses may be injection other than the intermittentinjection as long as the flow amount or the moving speed of fluid to beinjected changes periodically or irregularly.

The method of suction is now explained. The fluid injected from theinjection opening 72 remains on the surgery portion as drainage. Inaddition, excised tissues exist on the surgery portion. These drainageand excised tissues are sucked by the suction pump 11, and conveyed fromthe suction opening 82 through the suction channel 81 and the suctiontube 5 into the drainage container 3. The drive of the suction pump 11may be interlocked with the drive of the pulse generator 20, or may beperiodical intermittent drive.

There are a plurality of shapes and structures considered as suitablefor those of the injection pipe 70 and the suction pipe 80. These shapesand structures are herein discussed as specific examples while referringto the respective drawings.

First Example

A first example is now described.

FIG. 2 is a cross-sectional view showing cross sections of the pulsegenerator, the injection pipe, and the suction pipe cut in the injectiondirection of fluid according to the first example. The pulse generator20 includes an inlet channel 61 through which fluid is supplied from thesupply pump 10 via the fluid supply tube 4 toward the fluid chamber 60,the piezoelectric element 30 and the diaphragm 40 as the volume varyingunit for varying the volume of the fluid chamber 60, and an outletchannel 62 communicating with the fluid chamber 60.

The diaphragm 40 is constituted by a disk-shaped thin metal plate andfixed by tight contact with a lower case 50 and an upper case 52. Inthis embodiment, the piezoelectric element 30 is a laminated-typepiezoelectric element which has one end fixed to the diaphragm 40 via anupper plate 35 and the other end fixed to a bottom plate 51.

The fluid chamber 60 is a space defined by the diaphragm 40 and aconcave portion formed on the surface of the upper case 52 opposed tothe diaphragm 40. The outlet channel 62 opens approximately at thecenter of the fluid chamber 60.

The upper case 52 and the lower case 50 are combined into one body byjunction of the opposed surfaces of the upper case 52 and the lower case50 (with the diaphragm 40 interposed therebetween in the example of FIG.2). The injection pipe 70 which has the injection channel 71communicating with the outlet channel 62 engages with the upper case 52.The injection opening 72 having a reduced channel diameter is providedat the top end of the injection pipe 70. The injection opening 72 may beformed by a nozzle.

The suction pipe 80 as a jacket pipe for the injection pipe 70 projectsfrom the upper case 52. An opening 83 penetrating through the side wallof the suction pipe 80 is formed in the vicinity of the root end of thesuction pipe 80 close to the pulse generator 20, and the suction tube 5is attached to the opening 83 in such a condition as to communicate withthe opening 83. For an operator who holds the pulse generator 20 whileperforming operation, the maneuverability improves when the extendingdirection of the suction tube 5 in the vicinity of the pulse generator20 is equalized with the extending direction of the fluid supply tube 4.

As illustrated in the figure, the injection pipe 70 is eccentricallyinserted into the suction pipe 80. Thus, the outer circumferentialsurface of the injection pipe 70 and the inner circumferential surfaceof the suction pipe 80 contact each other, or are disposed with a smallclearance left therebetween in the range of the length of the suctionpipe 80. This condition is now explained with reference to FIGS. 3A and3B.

FIGS. 3A and 3B are cross-sectional views illustrating cross sectionscut along an A-A line in FIG. 2. FIG. 3A shows the cross section in thisexample, while FIG. 3B shows the cross section in a related art. Asillustrated in FIG. 3A, the outer circumferential surface of theinjection pipe 70 and the inner circumferential surface of the suctionpipe 80 contact each other. The clearance formed between the flowchannel of the suction pipe 80 and the outer circumferential surface ofthe injection pipe 70 corresponds to the suction channel 81. When theflow channel diameter of the suction pipe 80 and the outside diameter ofthe injection pipe 70 are d1 and d2, respectively, the length (d1−d2)becomes the maximum size of the suction channel 81.

According to the technology shown in JP-A-1-313047, the injection pipe70 is inserted concentrically with the suction pipe 80. In this case,the maximum size of the suction channel 81 becomes (d1−d2)/2. Thus, evenwhen the total areas of the respective suction channels 81 in thestructures of this example and JP-A-1-313047 are the same, the size ofthe suction channel 81 in the eccentric structure as in this examplebecomes larger than the size of the suction channel 81 in JP-A-1-313047.This relationship between the suction channels 81 in this example and inJP-A-1-313047 similarly applies to the relationship between the sizes ofthe suction openings 82 in both of the structures.

According to this example, the outer circumferential surface of theinjection pipe 70 contacts the inner circumferential surface of thesuction pipe 80. In this structure, the injection pipe 70 is insertedinto the suction pipe 80 and fixed thereto by an adhesive or the likeunder the condition of contact between the inner circumferential surfaceof the suction pipe 80 and the outer circumferential surface of theinjection pipe 70. Then, the suction pipe 80 and the injection pipe 70fixed to each other are attached to the upper case 52 with press fit forassembly. In this case, as illustrated in FIG. 2, the injection pipe 70is forced into the upper case 52 with the root end of the injection pipe70 on the upper case 52 side projecting from the root end of the suctionpipe 80, in which condition the suction pipe 80 engages with the uppercase 52 with play. Then, the fitted pipes 70 and 80 are fixed to theupper case 52 by using an adhesive or the like. It is preferable thatthe sealing of the fixation between the upper case 52 and the injectionpipe 70 and the suction pipe 80 is reinforced by using an adhesive, asolder or the like.

It is preferable that the injection pipe 70 and the suction pipe 80 arefixed to each other for the entire contacting areas of the respectivepipes 70 and 80 in the length directions. However, the pipes 70 and 80are only required to be fixed at least in the area around the top end ofthe injection opening 72 (a B range in FIG. 2). In this case, theinjection pipe 70 and the suction pipe 80 are inserted into the uppercase 52 in this order, and then the range B in the figure is fixed bybonding using an adhesive or a solder, or fixed by using a fixing methodsuch as welding.

It is preferable that each flow channel size of the opening 83 providedon the suction pipe 80 and the suction tube 5 is made equal to or largerthan the cross-sectional area of the flow channel of the suction opening82.

The pulse flow injection operation performed by the pulse generator 20according to this example is now explained with reference to FIGS. 1 and2. Fluid is supplied to the inlet channel 61 at a constant pressure bythe function of the supply pump 10. The fluid supply amount from thesupply pump 10 is only required to be approximately the same amount asthat of the pulse flow injection amount from the injection opening 72.While the piezoelectric element 30 is not actuating, fluid flows intothe fluid chamber 60 by the difference between the discharging force ofthe supply pump 10 and the resistance of the entire flow channel of theinlet channel 61.

When the piezoelectric element 30 rapidly expands in the verticaldirection with respect to the surface of the diaphragm 40 on the fluidchamber 60 side in response to a drive signal inputted to thepiezoelectric element 30, the volume of the fluid chamber 60 decreases.As a result, the pressure within the fluid chamber 60 sharply increasesto reach several tens atms.

In this case, the increase in the flow amount of the fluid dischargedfrom the outlet channel 62 becomes larger than the decrease in the flowamount of the fluid flowing from the inlet channel 61 into the fluidchamber 60, thereby generating pulse flow in the injection channel 71.This pressure change produced at the time of the discharge istransmitted through the injection pipe 70 to allow injection of pulsedfluid at high speed from the injection opening 72 at the top end.

As described above, the injection pipe 70 is eccentrically inserted intothe suction pipe 80 according to the first example. In this case, eachsize of the suction channel 81 and the suction opening 82 corresponds tothe difference between the inside diameter of the suction pipe 80 andthe outside diameter of the injection pipe 70. Thus, each size of thesuction channel 81 and the suction opening 82 in the eccentric structurebecomes larger than the corresponding size in the concentric structure.Accordingly, larger excised tissues can be sucked in the structure ofthe eccentrically disposed the injection pipe 70 and the suction pipe 80than in the concentric structure. Moreover, the drainage removal amountof injected fluid increases, which provides preferable vision forsurgery.

According to this example, the injection pipe 70 is fixed to the innercircumferential surface of the suction pipe 80 in the vicinity of theinjection opening 72. Thus, abnormal noise generated by contact betweenthe injection pipe 70 and the suction pipe 80 caused by vibration at thetop end of the injection pipe 70 during injection of pulse flow can beprevented. Moreover, resonance of the suction pipe 80 generated by thevibration at the top end of the injection pipe 70 (injection opening) isavoided, allowing accurate injection of fluid toward the surgeryportion.

While the structure which fixes the suction pipe 80 to the upper case 52has been discussed in this example, such a structure which expands theupper case 52 such that the upper case 52 can function as a suction pipeis allowed.

The position and extending direction of the suction tube 5 are notspecifically limited. However, since the operator holds the pulsegenerator 20 for performing operation, the system becomes well-balancedduring operation and provides higher maneuverability when the suctiontube 5 and the fluid supply tube 4 extend along each other in thevicinity of the pulse generator 20.

Second Example

A second example is now described with reference to the drawings. Whilethe injection pipe 70 and the suction pipe 80 are provided eccentricallyfor the entire lengths of the pipes 70 and 80 in the first exampledescribed above, the second example is different from the first examplein that only the top end areas of the injection pipe 70 and the suctionpipe are eccentrically disposed with the root end areas concentricallypositioned. In the explanation of the second example, similar referencenumbers are given to parts similar to the corresponding parts in thefirst example, and the different points between the first example andthe second example are chiefly discussed.

FIG. 4 is a partial cross-sectional view illustrating the structures ofthe injection pipe and the suction pipe according to the second example.The root end of the suction pipe 80 is fixed to the upper case 52 withpress fit. The root end of the injection pipe 70 is fixed to the uppercase 52 with press fit in such a condition as to be concentric with thesuction pipe 80. The top ends (the B area in the figure) of theinjection pipe 70 and the suction pipe 80 are fixed to each other bybonding such as an adhesive and a solder, or by using a fixing methodsuch as welding.

According to this structure, the condition visually recognized on thetop end side is similar to the condition shown in FIG. 3A, and the sizeof the suction opening 82 in this structure becomes larger than thecorresponding size in the concentric structure. Thus, larger excisedtissues can be sucked than in the related art which concentricallydisposes the top ends of the injection pipe 70 and the suction pipe 80.Since clogging with excised tissues is easily caused at the suctionopening 82, the sucking capability can be increased by widening thesuction opening 82.

According to the structure which concentrically disposes the root endsof the injection pipe 70 and the suction pipe 80, the upper case 52 canbe more easily processed than in the structure which fixes theeccentrically disposed pipes 70 and 80 to the upper case 52 as in thefirst example. Thus, the respective pipes 70 and 80 can be more easilyattached to the upper case 52 with press fit.

The injection pipe 70 may be bended beforehand and urged toward theinner circumferential surface of the suction pipe 80 by the elasticforce of the injection pipe 70. In this case, the suction pipe 80 ismade rigid enough to resist the elastic force of the injection pipe 70and to prevent vibration of the suction pipe 80. According to thisstructure, the process for fixing the top ends of the pipes 70 and 80can be eliminated.

Third Example

A third example is now described with reference to the drawings. Thethird example is different from the second example in that the positionof connection between the suction pipe 80 and the suction tube 5 isdifferent from the corresponding position in the second example. In thefollowing explanation, similar reference numbers are given to partssimilar to the corresponding parts in the second example, and thedifferent points between the second example and the third example arechiefly discussed.

FIG. 5 is a partial cross-sectional view illustrating the structures ofthe injection pipe and the suction pipe according to the third example.The relationship between the injection pipe 70 and the suction pipe 80is similar to that relationship in the second example. According to thesecond example, the top ends of the injection pipe 70 and the suctionpipe 80 are eccentrically disposed and fixed to each other. Thus, thearea of the suction channel 81 other than the fixed portion graduallydecreases toward the root end, and becomes a channel of the same size asthat size in the concentric structure in the vicinity of the opening 83where the suction tube 5 is disposed. However, it is preferable that theopening 83 is provided in the range where the suction channel 81 iswide.

According to this example, therefore, an opening position C is disposedat a position where the suction channel 81 is relatively wide. In thisstructure, a tube fitting 90 having a connection channel 91 is used. Theconnection channel 91 is bended approximately in an L shape such thatthe suction tube 5 extends along the suction tube 80 and further alongthe fluid supply tube 4 (see FIG. 2). In this case, the suction tube 5may be formed in the manner shown in the figure, or may be bound to thesuction pipe 80 by using a binding band (not shown) around a point D inthe figure when the suction tube 5 has sufficient elasticity.

According to this structure, the opening 83 is disposed at the positionwhere the suction channel 81 becomes wider than in the concentricstructure. Thus, the sucking capability does not lower. Moreover, incase of this structure, the area of the suction tube 5 around the tubefitting 90 extends along the suction pipe 80, and the area of thesuction tube 5 around the pulse generator 20 extends along the fluidsupply tube 4. Thus, the pulse generator 20 can be easily held, whichdoes not deteriorate the maneuverability.

Furthermore, the structure of the upper case 52 to which the root endsof the injection pipe 70 and the suction pipe 80 are attached can besimplified.

It is possible to form the tube fitting 90 and the suction pipe 80integrally with each other, or form the tube fitting 90 and the suctiontube 5 integrally with each other.

Fourth Example

A fourth example according to the invention is now described withreference to the drawings. The fourth example is different from thethird example in that the injection pipe 70 is bended at a positionwithin the area between the root end and the top end to fix the top endsof the injection pipe 70 and the suction pipe 80 to each other. In thefollowing explanation, similar reference numbers are given to partssimilar to the corresponding parts in the third example, and thedifferent points between the third example and the fourth example arechiefly discussed.

FIG. 6 is a partial cross-sectional view illustrating the structures ofthe injection pipe and the suction pipe according to the fourth example.The injection pipe 70 and the suction pipe 80 are attached to the uppercase 52 such that the pipes 70 and 80 become concentric with each othersimilarly to the second example and the third example described above.According to this example, the injection pipe 70 is bended approximatelyat the center. The area of the injection pipe 70 between the top end anda bended portion 70 a contacts the inner circumferential surface of thesuction pipe 80, and is fixed thereto by bonding such as an adhesive anda solder, or by using a fixing method such as welding. The area of theinjection pipe 70 between the bended portion 70 a and the root end isapproximately concentric with the suction pipe 80.

The opening 83 formed on the suction pipe 80 (the opening position C) isdisposed at a position shifted from the bended portion 70 a toward thetop end and communicates with the suction tube 5 via the tube fitting90. The suction tube 5 extends along the fluid supply tube 4.

According to this structure, the opening 83 is provided at a positionwithin the area between the suction opening 82 and the bended portion 70a where the suction channel 81 is wide. Thus, the suction channel 81having approximately the same size as that of the suction opening 82 canbe formed, which allows larger excised tissues to be removed by suctionthan in the concentric structure.

When the bended portion 70 a is positioned closer to the root end, theopening 83 of the suction pipe 80 can be shifted toward the pulsegenerator 20. In this case, the pulse generator 20 can be easily held,which improves the maneuverability. When the bended portion 70 a isdisposed within the area of the upper case 52, the opening 83 can beprovided on the upper case 52 similarly to the structure of the secondexample (see FIG. 4).

Fifth Example

A fifth example is now described with reference to the drawings. Thefifth example is different from the first example in that the suctionpipe 80 linearly formed in each of the first through fourth examples isbended in the middle area. In case of an abdominal cavity surgery or thelike performed by using the fluid injection device 1, there is apossibility that the surgery portion is not located on a straight lineextending from the position on the body surface into which the suctionpipe 80 is inserted. In this case, the top ends of the injection pipe 70and the suction pipe 80 are required to be located at bended positionswith respect to their root ends. This example is appropriate for thiscase. In the following explanation, similar reference numbers are givento parts similar to the corresponding parts in the second example onwhich the fifth example is based.

FIG. 7 is a partial cross-sectional view illustrating the structures ofthe injection pipe and the suction pipe according to the fifth example.The suction pipe 80 is bended at a middle position in the area betweenthe top end and the root end. The injection pipe 70 is bended along theinner circumferential surface of the suction pipe 80, and fixed to theinner circumferential surface of the suction pipe 80 in the area aroundthe injection opening 72 (the B range in the figure) by bonding using anadhesive, a solder or the like, or by a fixing method such as welding.

There is a method which bends the injection pipe 70 in accordance withthe shape of the suction pipe 80. In practice, however, insertion of abended tube into another bended tube is difficult from the viewpoint ofstructure. Thus, the substantially linear injection pipe 70 is initiallyfixed to the upper case 52 with press fit, and then the suction pipe 80is inserted from the injection opening 72 side. In this case, the topend of the injection pipe 70 contacts a slope 80 a at the bendingposition of the suction pipe 80, and then is bended in accordance withthe shapes of the slide 80 a and a bended portion 80 b with to obtain ashape shown in FIG. 7 when the root end of the suction pipe 80 reachesthe upper case 52. In case of the abdominal cavity surgery, each lengthof the injection pipe 70 and the suction pipe 80 is approximately in therange from 200 m to 400 mm. Thus, the actual bending angle becomes agentler angle than the angle in the condition shown in the figure.

According to this example, therefore, the top ends of the injection pipe70 and the suction pipe 80 can be eccentrically disposed even when thetop ends of the injection pipe 70 and the suction pipe 80 are located atbended positions with respect to their root ends in correspondence withthe surgery portion or the surgery method. Thus, the suction opening 82in this structure becomes wider than in the concentric structure. Inthis example, the bended portion of the suction channel 81 has an areasmaller than the suction opening 82. However, since the outer shape ofthe injection pipe 70 is circular, the resistance of the flow channel issmall enough to avoid lowering of the capability of sacking the excisedtissues.

According to this example, the injection pipe 70 is inserted along theinner circumferential surface of the bended suction pipe 80. Thus, thetop end of the injection pipe 70 is urged toward the innercircumferential surface of the suction pipe 80 by the elastic force ofthe injection pipe 70. Accordingly, the top end of the injection pipe 70is not required to be fixed as long as the urging force is large enoughto prevent vibration. Considering this point, the rigidity of thesuction pipe 80 is made larger than the rigidity of the injection pipe70.

Sixth Example

A sixth example is now described with reference to the drawings. Thesixth example is different from the first through fifth examples in thatthe fluid injection direction which extends on a straight line drawnfrom the injection channel 71 or in parallel with the injection channel71 in each of the first through fifth examples is inclined to theinjection channel 71. There is a case in which excision is performed ata position shifted from the extending direction of the suction pipe 80depending on the surgery portion. This example is appropriate for thiscase. In the following explanation, similar reference numbers are givento parts similar to the corresponding parts in the first example onwhich the sixth example is based.

FIG. 8 is a partial cross-sectional view illustrating the structures ofthe injection pipe and the suction pipe. The top ends of the injectionpipe 70 and the suction pipe 80 are bended, and the injection pipe 70follows the inner circumferential surface of the bended portion of thesuction pipe 80. The area of the injection pipe 70 around the injectionopening 72 is fixed to the inner circumferential surface of the suctionpipe 80 by using an adhesive, a solder or the like, or by a fixingmethod such as welding.

When the flow channel diameter of the suction pipe 80 and the bendingheight of the injection pipe 70 are d1 and h, respectively, the flowchannel diameter d1 is determined such that the relationship h<d1 holds.This arrangement allows insertion of the injection pipe 70 into thesuction pipe 80.

According to this structure, excision and removal of excised tissues bysuction at a position shifted from the extending direction of thesuction pipe 80 can be achieved in accordance with the surgery portion.

The structure in this example maybe applied to each structure of thefirst through fifth examples.

Seventh Example

A seventh example is now described with reference to the drawings. Sincethe injection opening 72 is disposed eccentrically to the suctionopening 82 as described in each of the examples, it is difficult for theoperator to directly recognize the injection opening 72 by visual check.For overcoming this drawback, a feature of the seventh example residesin that a mark representing the position of the injection opening 72 isprovided in the vicinity of the suction opening 82.

FIGS. 9A and 9B illustrate the top ends of the injection pipe and thesuction pipe according to the seventh example. FIG. 9A is across-sectional view, and FIG. 9B is a front view as viewed from the topend (in the direction indicated by an arrow E). As illustrated in FIGS.9A and 9B, a notch 73 as a mark is formed on the suction pipe 80 in thevicinity of the injection opening 72. The notch 73 is formed in such aposition and a shape as to overlap with the periphery of the suctionopening 82. Thus, the operator can visually recognize the top end of theinjection pipe 70 (injection opening position).

The mark may be a notch as shown in the figure, or other marks such as aseal, a small hole, and a paint provided on the outer circumferentialsurface of the suction pipe 80. When the mark is the notch 73 as in thisexample, the operator can directly recognize the position of theinjection opening 72 by visual check during operation. Thus, theoperator can inject fluid to the accurate surgery portion for excision.

Eighth Example

An eighth example is now described with reference to the drawings. Whilethe one notch 73 is provided as a mark in the seventh example, theeighth example is different in that the mark is constituted by notchesformed in such positions as to overlap with the suction opening orthrough holes opened in the vicinity of the suction opening.

FIG. 10 is a front view illustrating the top end of the suction pipeaccording to the eighth example. As illustrated in FIG. 10, four notches73 a, 73 b, 73 c, and 73 d are formed on the top end of the suction pipe80 in such positions as to overlap with the periphery of the suctionopening 82. According to the example shown in FIG. 10, the notch 73 acorresponds to a mark indicating the position of the injection opening72. The other notches 73 b through 73 d are provided to supplement thesucking function of the suction opening 82. Thus, the notch 73 a has aposition and shape appropriate for a mark, while the other notches 73 bthrough 73 d have positions and shapes allowing suction of excisedtissues. The notches 73 a through 73 d may be through holes (not shown)penetrating the side surface of the top end of the suction pipe 80.

Accordingly, the mark indicating the position of the injection opening72 can be provided in the vicinity of the suction opening 82 byformation of the notches 73 a through 73 d. These notches 73 a through73 d can further supplement the size of the suction opening 82, and thuscan increase the capability of sucking excised tissues.

Furthermore, the through holes formed in the vicinity of the suctionopening 82 can remove excised tissues existing on the side surface ofthe top end by suction.

1. A fluid injection device comprising: a pulse generator which convertsfluid into pulse flow; a suction pipe projecting from the pulsegenerator; an injection pipe which is eccentrically inserted into thesuction pipe such that the outer circumferential surface of theinjection pipe contacts the inner circumferential surface of the suctionpipe, and has an injection opening communicating with the pulsegenerator; and a suction channel and a suction opening formed betweenthe inner circumferential surface of the suction pipe and the outercircumferential surface of the injection pipe, wherein the injectionpipe is fixed to the inner circumferential surface of the suction pipein the vicinity of the injection opening.
 2. The fluid injection deviceaccording to claim 1, wherein a mark indicating the position of theinjection opening is provided on the suction pipe in the vicinity of thesuction opening.
 3. The fluid injection device according to claim 2,wherein the mark is a notch formed in such a position as to overlap withthe periphery of the suction opening, or a through hole opened in thevicinity of the suction opening.